Piezoelectric Hafnium Oxide Thin Films for Energy-Harvesting Applications

Abstract

This paper presents the piezoelectric properties of silicon doped hafnium oxide (Si:HfO2) thin films and their superior suitability for energy harvesting applications. Various layer thicknesses from 10 nm to 50 nm, executed as single layer and in a laminate structure, are investigated. The piezoelectric coefficient d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33,f</sub> of the samples is measured via double beam laser interferometry (DBLI) and converted into d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> , based on a numerical simulation model. Values of up to d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> =73 pm/V are obtained. Finally, the Si:HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films are electrically investigated by evaluating a relative permittivity between 37 and 47, respectively.